Pigment and power dressing in Roman Egypt

This is my favourite post on the British Museum blog (it appeared a couple of years ago). Now that you know about ancient polychromy research and Egyptian blue I can share it with you and it should make sense. (Or you might just think archaeologists and conservation scientists are crazy and this Egypto-Roman sculpture of Horus was actually created by Jim Henson.) Enjoy!

British Museum blog

Limestone sculpture of Horus from Roman EgyptElisabeth R. O’Connell, curator, British Museum

‘That’s one weird looking bird,’ grinned an American student on one of my tours of the Ancient Egypt and Sudan Department study collection for university students last year.

And to Egyptology students he is. And to students of Classical Archaeology too. But that’s rather the point. Roman Egypt (30 BC-AD 642) witnessed some of the most interesting, innovative and transformative combinations of traditions in the ancient world.

The god sits casually on his throne, one sandal-clad foot forward, his knees apart and draped in a garment. From the waist down, he could be any of a number of senior Olympian deities, or Roman emperors masquerading as such. He wears a feathered mail armour shirt that ends just above his elbows. His arms, now broken off, would have held symbols of power, perhaps an orb and sceptre. His cloak, pushed back over his shoulders…

View original post 718 more words

Advertisements

Seeing Red: VIL and IRR

In addition to UVF, we did Visible-Induced Luminescence (VIL) imaging on all the sculptures and, a couple of times, we did Infrared Reflectography (IRR) as well. In both cases, imaging is done in the near infrared range of the light spectrum. I will focus on VIL, but IRR is essentially the same (or so Mark tells me), but we used a red LED spotlight to illuminate the objects rather than the flashes. This makes for much more interesting photos and that’s why I’m briefly mentioning it here. (IRR is also regularly used in the study of paintings because it allows you to see preliminary sketches (underdrawings) underneath the layers of paint—that’s actually pretty cool.)

The setup for VIL is the same as UVF, but you mustn’t forget to change the camera and the filters on the flashes! Basically, we’d do UVF and VIL one after the other so the camera angles and distances remained the same for both series of photographs. Of course, before you do all that, you also have to take ambient light photographs of the sculpture. And to each series, you take one photo with the grey card… and another with the colour card, if it’s not already in the shot. It was a lot to think about, but we came up with a routine and all went smoothly. Although there were a couple of times when we forgot to change the camera… (Ah, hum, well, you know, we were working late in the dark galleries of the museum.)

VIL is used to detect traces of Egyptian blue—the first synthetic pigment ever made, used for thousands of years in ancient Egypt and known throughout the ancient Mediterranean. Naturally occurring blue minerals were either too precious or difficult to transform into large quantities of blue powder to create blue paint, so the Egyptians invented an artificial pigment.

Egyptian blue has the peculiar property of emitting infrared radiation when excited with a red light. Traces of Egyptian blue can easily be detected in the infrared spectrum—the pigment will glow a bright white. None of this is actually visible to the naked eye; shine as much red light as you want onto a work of art, you will not see the luminescence (bright white glow) because human vision does not extend to that part of the light spectrum. However, if you have an infrared (night vision) camera (usually a modified digital SLR camera with infrared filters), you can take an image of that luminescence. That’s what we did. We took photographs of all ancient marbles with the infrared camera when we used the flashes to excite the pigments. We found traces of Egyptian blue pigment on a few objects—some deliberately painted (like the sarcophagus fragment), others having been in contact with particles of the pigment but not actually decorated with it. (You can figure this out normally by the pattern or distribution of the luminescence.) The luminescence is so strong you can actually see single grains of Egyptian blue!

There is a great video about Egyptian blue on the British Museum website, click here to view it.  One of the photos below features Jimmy in the process of posting an image to Instagram.  To see what he posted, click here!

 

UVF: Night at the Museum

I thought I would start my series of posts about the scientific methods we used for the study of the marbles with Ultraviolet Fluorescence Imaging (UVF imaging). Works of art are regularly examined under ultraviolet light because it reveals restorations, retouches, varnishes as well as some colour pigments, which have characteristic fluorescence under UV. (Ultraviolet light is often called ‘black light,’ something you’ll be familiar with if you’ve ever set foot in a night club.)

UVF examination and imaging needs to be done in the dark, so we worked in the small x-ray suite in the conservation lab. There are no windows there, and by closing the door, we had all the darkness we needed to look at the small marble objects (they were taken out of the galleries for the study). However, for the large sculptures (which could not be moved), we had to be in the museum galleries at night! That was a little strange…

Simple UV examination can be done with a hand-held UV lamp, which you shine on the work of art as you look at it closely (wearing protective goggles). UVF imaging necessitates a digital SLR camera equipped with UV filters set up on a tripod. The camera is controlled by a computer and photos are taken when UV light is shone on it (either with large lamps, as in the case of Hercules, or hand-held flash with a UV filter). With the photographs, you then have a record of the fluorescence of the pigments and other surface treatments and their location.

Doing UVF was like travelling back to the 80s: the ultraviolet lights, the neon colours, the bright white, and the music playing from my iPod. We had a blast! As I have had this incredible urge to watch Blade Runner since we looked at Hercules under UV on June 22, I put it on my Netflix list… and the DVD arrived today. Enjoy the post and pictures while I watch Harrison Ford and Sean Young in this 1982 sci-fi movie.

Pigment Busters

Following my ‘Searching for Colour!’ post, I got a few questions from family, friends and colleagues asking why we were actually looking for colour on our ancient marble sculptures.

We were looking for colour pigments on the marble sculptures because in ancient times most would have been coloured in some way! It seems inconceivable to us that these beautiful white marble sculptures could ever have had paint on them. But they often did. (Sounds gaudy, doesn’t it?) Sometimes, only details were painted; other times, they were completely covered by pigments or maybe part of them would have been gilded (covered in gold leaf). Or even perhaps have parts carved from coloured marble and assembled as one sculpture. This applies to Egyptian and other ancient sculpture as well (although those are not necessarily carved from marble).

Most ancient marble sculptures are now devoid of colour, the sun and rain having bleached or washed them away over the millennia. Thought to be ‘white,’ these ancient marble sculptures were the inspiration for statues carved during the Renaissance or the Neo-Classical period and those were NOT painted. That’s how we normally think of marble sculptures… white, the typical colour of marble. However, in nooks and crannies, you can occasionally find proof that coloured pigments were applied to those sculptures—in some cases visible with the naked eye.

During the two intense weeks of Classical marble study (and using various methods), Mark, Elizabeth, Noelle, Marianne and I went pigment busting…

 

Is this thing set to stun?

I’m exhausted. The last two weeks have been rather hectic, to say the least. There were several evenings when I didn’t get home until after 11pm… We’ve worked very hard on the classical marbles: we’ve examined the statues like we’ve never done before at the museum and used some weird equipment, too—it was great fun!

I’m too tired to go into details right now, so I thought I would share photos today and describe the various studies in later posts when I’m actually awake and coherent.

 

Searching for colour!

This week, I’m entirely focused on the Classical marbles in the NCMA’s collection and we’re doing some pretty cool stuff: we’re searching for colour on the marble sculptures! I’m working with Mark Abbe, asst. prof. of ancient art at the University of Georgia, Athens—a specialist of marble statuary and ancient polychromy. I’ll keep details for later when I can actually show you photos of us in action when I post on Untitled, the NCMA blog; however, I want to let you know that I have a good excuse for being somewhat silent at present!